by Wendy Gabriel
Every day, we use a multitude of different products: alarm clocks, clothes, backpacks, shoes, books, CD/DVD players, cell phones and the list goes on. Looking at a product’s life cycle helps us understand the connections between our purchases and the impact they make on our environment.
The life cycle of a CD or a DVD
CDs and DVDs are made from many different materials, each of which has its own separate life cycle involving energy use and waste. They include:
- Aluminum—the most abundant metal element in the Earth’s crust. Bauxite ore is the main source of aluminum and is extracted from the Earth.
- Polycarbonate—a type of plastic, which is made from crude oil and natural gas extracted from the Earth.
- Lacquer—made of acrylic, another type of plastic.
- Gold—a metal that is mined from the Earth.
- Dyes—chemicals made in a laboratory, partially from petroleum products that come from the Earth.
- Other materials such as water, glass, silver, and nickel.
Most mined materials must be processed before manufacturers can use them to make CDs or DVDs. For example, to make plastics, crude oil from the ground is combined with natural gas and chemicals in a manufacturing or processing plant.
The manufacturing process described is similar for both CDs and DVDs.
- An injection molding machine creates the core of the disc—a 1-millimeter thick piece of polycarbonate (plastic). Polycarbonate is melted and put in a mold. With several tons of pressure, a stamper embeds tiny indentations, or pits, with digital information into the plastic mold. A CD-player’s laser reads these pits when playing a CD.
- The plastic molds then go through the “metallizer” machine, which coats the CDs with a thin metal reflective layer (usually aluminum) through a process called “sputtering.” The playback laser reads the information off of the reflective aluminum surface.
- The CD then receives a layer of lacquer as a protective coating against scratching and corrosion.
- Most CDs are screen printed with one to five different colors for a decorative label. Screen printing involves the use of many materials, including stencils, squeegees,and inks.
CDs and DVDs are packaged in clear or colored plastic cases (jewel cases) or cardboard boxes—that are then covered with plastic shrink wrap. This packaging can be made from recycled or raw materials.
Here are some tips for Reducing, Reusing and Recycling
Instead of purchasing a new CD or DVD consider:
- Borrowing it from a friend or the library.
- Renting it from a local shop or a service like Netflix.
- If you’re buying it for data storage, use an external hard drive or a service that keeps your files updated.
- Buy used CDs/DVDs.
A great way to keep CDs/DVDs out of the landfills is to reuse them.
- Minor scratches can be repaired by rubbing a mild abrasive (such as toothpaste) on the non- label side of a disc in a circular motion from the center out. Also, some commercial refinishers can inexpensively repair your CDs.
- Donate unwanted CDs or DVDs to your local resale shop, schools or libraries.
- Swap unwanted discs at Freecycle.org.
CDs/DVDs can be recycled for use in new products. Specialized electronic recycling companies clean, grind, blend and compound the discs into a high-quality plastic for a variety of uses.
Check out CDRecyclingCenter.org for information on how to send your CDs/DVDs for recycling.
My Green Side’s web pick of the week:
1800Recycling.com is an awesome recycling and green living-focused website that makes recycling, conserving, reusing and living wisely easy.
The site features a recycling location database that gives the user the ability to easily assemble a recycling to-do list. The database is location based, and aims to make your recycling needs as easy as possible, whether you’re clearing out the house during spring cleaning or simply looking to recycle a few shopping bags.
Editor’s Note: Each Wednesday My Green Side brings Simple Tips for Green Living to The Christopher Gabriel Program. We also highlight a favorite green site each week. You can stream the segment at approximately 1220pm (central) every Wednesday at WDAY.com.